The recent negotiations between Turkish President Recep Tayyip Erdogan and Russian Defense Minister Sergei Shoigu in Istanbul have been positive, with Turkey expressing its concerns over rising activity of the Kurdish armed groups in Syria, Turkish Deputy Prime Minister Numan Kurtulmus said Monday.

On Sunday, the Turkish presidential press service reported that Erdogan received Shoigu, however without clarifying additional details. On Monday, Erdogan’s spokesman said that the officials discussed a number of issues, including the creation of de-escalation zones in Syria and a conflict settlement road map.

“The groups in Syria receiving political and military support from abroad pose a threat to Turkey’s national security. Turkey is very sensitive about this issue, especially in Afrin, where terrorist troops exist, and the Russian side, as well as the US side, know this. During the visit of the Russian minister we expressed our concerns to him. The negotiations [between Erdogan and Shoigu] ended in a positive way,” Kurtulmus said at a press conference.

The Turkish official added that Ankara’s cooperation with Moscow and Tehran was continuing, and the Turkish side could see that its counterparts from Russia understand their concerns.

Afrin is located in the province of Aleppo and belongs to the de facto autonomous region of Rojava in the north of Syria. Turkey considers the Syrian Kurdish associations to be a wing of the Kurdistan Workers’ Party (PKK).